On November 5, 2018 5:11:09 PM GMT+01:00, Jan Hubicka <hubi...@ucw.cz> wrote:
>> Hi,
>> this is patch I ended up testing. It ensures that canonical types of
>> copies I create are same as of originals C++ FE has its own refernece
>piece of mail got lost rendering the paragraph unreadable. I wanted to
>say:
>
>This is patch I ended up testing. It ensures that canonical types of
>copies I create are same as of originals. It however ICEs building
>auto-profile.c because C++ FE has its own reference type construction
>(cp_build_reference_type) and it creates additional pointer types with
>TYPE_REF_IS_RVALUE set and it has different TYPE_CANONICAL.
Hmm. I guess we need to fix that, otherwise alias will be broken (or you need
to resort to a FE specific routine for pointer building).
Richard.
>> Obviously we do not see this in middle-end and we end up merging the
>> types despite fact they have different TYPE_CANONICAL.
>> I guess I can immitate the behaviour in fld_incomplete_type_of by
>> implementing my own variant of build_pointer_type that also matches
>> TYPE_CANONICAL of the pointer it creates. I wonder if there are
>better
>> solutions?
>>
>> Honza
>>
>> Index: tree.c
>> ===================================================================
>> --- tree.c (revision 265807)
>> +++ tree.c (working copy)
>> @@ -5118,6 +5118,7 @@ fld_type_variant (tree first, tree t, st
>> TYPE_ADDR_SPACE (v) = TYPE_ADDR_SPACE (t);
>> TYPE_NAME (v) = TYPE_NAME (t);
>> TYPE_ATTRIBUTES (v) = TYPE_ATTRIBUTES (t);
>> + TYPE_CANONICAL (v) = TYPE_CANONICAL (t);
>> add_tree_to_fld_list (v, fld);
>> return v;
>> }
>> @@ -5146,6 +5147,10 @@ fld_incomplete_type_of (tree t, struct f
>> else
>> first = build_reference_type_for_mode (t2, TYPE_MODE (t),
>> TYPE_REF_CAN_ALIAS_ALL (t));
>> + gcc_assert (TYPE_CANONICAL (t2) != t2
>> + && TYPE_CANONICAL (t2) == TYPE_CANONICAL (TREE_TYPE (t))
>> + && TYPE_CANONICAL (first)
>> + == TYPE_CANONICAL (TYPE_MAIN_VARIANT (t)));
>> add_tree_to_fld_list (first, fld);
>> return fld_type_variant (first, t, fld);
>> }
>> @@ -5169,6 +5174,7 @@ fld_incomplete_type_of (tree t, struct f
>> SET_TYPE_MODE (copy, VOIDmode);
>> SET_TYPE_ALIGN (copy, BITS_PER_UNIT);
>> TYPE_SIZE_UNIT (copy) = NULL;
>> + TYPE_CANONICAL (copy) = TYPE_CANONICAL (t);
>> if (AGGREGATE_TYPE_P (t))
>> {
>> TYPE_FIELDS (copy) = NULL;
